An experimental analysis of a Nd:YAG laser cutting process for machining silicon nitride

The ceramic silicon nitride was machined with a short pulsed Nd:YAG laser. The cuts made were crack free and exhibited promising characteristics for precision laser machining of such materials. The cut kerf geometry was analysed and modelled as a function of energy density. This model proved fairly accurate for lower level energy densities, but the amount of material removed increased with energy density up to a maximum point and then began to decrease. This work shows that laser machining silicon nitride can be accomplished with no crack formation and that the kerf characteristics can be modelled using an energy density formulation.